Bluetooth used to track people's movements

By Claudine Beaumont, Digital Channel Editor

Bluetooth mobile phone technology is being used to monitor the movement of tens of thousands of people, without their consent.

A research project has installed Bluetooth scanners in offices, cafes, shops, and pubs to monitor how people move around cities. But the residents of Bath, who are at the centre of this research, are unaware that their mobile phones and laptops are communicating with the scanners.

The team behind the project, Cityware, stresses that the scanners are not able to personally identify individuals, but privacy groups have expressed concerns about the scheme. The Information Commissioners' Office, which deals with data protection and privacy legislation, said it was "monitoring" the experiment.

Bluetooth is a type of short-range wireless technology found on most modern mobile phones, as well as portable digital devices such as PDAs and laptop computers. It provides a simple way for different machines to connect with one another over a small area of just a few metres, usually to allow the transfer of files between devices.

These signals are assigned an identity, which most people change to their name, initials or a pseudonym to make it easier to identify their device when they are trying to transfer files to it. Privacy experts argue that this can identify individual users to varying degrees, and thus could be used to build a picture of the shopping habits and movements of people.

There are more than 10 scanners in Bath, and more than 1,000 elsewhere in the world, after Cityware made the software freely available through sites such as Facebook. In Bath alone, about 3,000 people are being spotted each weekend, and about 250,000 people have been logged by Cityware scanners across the globe.

People can ensure their mobile devices cannot be spotted by these scanners simply by turning their Bluetooth signal off, and only enabling this technology when strictly necessary.

However, Rosemary Jay, a data and privacy expert with law firm Pinsent Masons, warns that not all mobile phone owners will understand how to do this: "Most ordinary users may not have the knowledge to make their devices 'invisible', so they are less technologically expert than the researchers tracking them," she said. "It is an example of how the lack of sophistication in ordinary users of these sort of technologies leaves them at a disadvantage compared to the developers, the IT teams and the sophisticated users.

"It is an imbalance society has to try to address."